The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Articles that are formed partially or wholly from composite materials (herein after referred to as “composite articles”) are employed in a vast number of fields, usually to provide the finished article with desired characteristics, such as a relatively low weight and a relatively high strength. One method of fabricating composite articles includes the use of strips of a composite material, such as a graphite tape or cloth, to form what is known in the art as a composite “lay-up”. The lay-up includes one or more layers, with each layer being formed from touching and/or overlapping strips of the material. A resin, which may be pre-impregnated in the material or later injected into one or more of the layers of material, is later processed to cure the lay-up such that the material strips are bonded together. Typically, the lay-up is formed on a mandrel having a formed work surface that conforms to the desired geometry of the finished composite article. Since the lay-up is relatively flexible and unable to support itself prior to curing, the mandrel is usually employed to support the lay-up during the curing process.
Known methods for the fabrication of composite articles include manual and automated fabrication. Manual fabrication entails manual cutting and placement of material by a technician to a surface of the mandrel.
This method of fabrication is time consuming and cost intensive, and could possibly result in non-uniformity in the lay-up.
Known automated fabrication techniques include flat tape laminating machines (FTLM) and contour tape laminating machines (CTLM). Typically, both the FTLM and the CTLM employ a solitary composite material dispenser that travels over the work surface onto which the composite material is to be applied. The composite material is typically laid down a single row (of composite material) at a time to create a layer of a desired width and length. Additional layers may thereafter be built up onto a prior layer to provide the lay-up with a desired thickness. FTLM's typically apply composite material to a flat transfer sheet or scrim. The transfer sheet and lay-up are subsequently removed from the FTLM and placed onto a mold or on a mandrel. In contrast, CTLM's typically apply composite material directly to the work surface of a mandrel.
The specifications for many composite articles further require that the composite material of each layer be applied in a predetermined orientation, with the orientations of each layer being different. To vary the orientation of the composite material in the layers, typically either the tape dispenser is moved at different angles relative to the mandrel or transfer sheet, or the mandrel or transfer sheet is manually shifted relative to the tape dispenser. The batch processing employed in known automated tape laminating devices can be slow, tedious, and cumbersome. Therefore, there is a need for an automated process that expedites the fabrication of and increases the quality of composite lay-ups.
A wide variety of structures can be fabricated from laminated tape using CTLM, FTLM, or manually. One such example is laminated tape aircraft structures, many of which are prepared with CTLM, FTLM, or manually laminated tape. Because many existing CTLM and FTLM have a single tape dispensing head and a relatively low throughput (e.g., typically three to five pounds per hour per machine), however, these machines can be a bottleneck during aircraft product, especially for large commercial aircraft which can have thousands of pounds of composite structures.